Pre-adjustable mechanical collimator interface

ABSTRACT

The invention relates to a mounting device for mounting a beam manipulating device of an X-ray apparatus to a radiation source of the X-ray apparatus, said mounting device comprising a first mounting flange ( 10 ) associated with the radiation source, a second mounting flange ( 20 ) associated with the beam manipulating device, and fastening means ( 60 ) for fixing the first mounting flange ( 10 ) and the second mounting flange ( 20 ) to each other. It is an object of the invention to facilitate the alignment of the X-ray beam manipulating device with respect to an X-ray beam path or an X-ray beam focus of the radiation source. To achieve this, the alignment means ( 30 ) are adapted to be fastened to the first mounting flange ( 10 ), the first mounting flange having a first reference surface ( 31 ) which is in a predetermined spaced relationship with respect to the X-ray beam path. The first reference surface ( 31 ) corresponds with a second reference surface ( 34 ) of the second mounting flange ( 20 ). Furthermore, the invention provides a method for mounting a beam manipulating device to a radiation source of an X-ray apparatus.

The invention relates to a mounting device for mounting a beammanipulating device of an X-ray apparatus to a radiation source of theX-ray apparatus, said mounting device comprising a first mounting flangeassociated with the radiation source, a second mounting flangeassociated with the beam manipulating device, and fastening means forfixing the first mounting flange and the second mounting flange to eachother.

It is generally known in the art to manufacture X-ray apparatuses insuch a way that the radiation source with its housing and additionaldevices for manipulating the X-ray beam, such as collimators, diaphragmsor shutters, are produced as separate components. Consequently, theseparate components have to be mounted to each other.

When mounting a beam manipulating device of an X-ray apparatus to theradiation source of the apparatus it is required to achieve exactalignment of the manipulating device in relation to the radiationsource, so as to make sure that the X-ray beam passes from the sourceand through the manipulating device along a certain path. To achievethis alignment, it is known from U.S. Pat. No. 2,542,196 to provide acertain displaceability of the beam manipulating device with respect tothe radiation source. By virtue thereof, the beam manipulating devicecan be adjusted with respect to the beam, which is emitted by theradiation source. Once the manipulating device has been adjusted withrespect to the beam, e.g. the radiation source, it is known to usefastening means, such as screws or bolts, to fasten the manipulatingdevice to the radiation source or the housing of the radiation source.

As described above, the adjustment of the beam manipulating device withrespect to the beam has to be performed in a very precise manner. Toachieve an exact alignment in the production process, it is known to useauxiliary means for detecting the beam and its direction, to assist inthe aligning process. During this process, X-rays and an appropriateX-ray protection room are required for the X-ray-system, as a result ofwhich the process is both time consuming and expensive. Additionally, itis necessary to replace or exchange the X-ray tube, which has a shorterlifetime than the other system components. This replacement or exchangeis usually to be performed by a maintenance mechanic, so that auxiliarymeans used in the production process are not available. As a result, thealignment of the manipulating device with respect to the beam of thesystem is even more time consuming than during the production process inthe factory.

It is an object of the invention to provide a mounting device of thekind mentioned in the opening paragraph which facilitates the alignmentof an X-ray beam manipulating device with respect to an X-ray beam path,or with respect to an X-ray beam focus, of a radiation source of anX-ray apparatus.

To achieve this object, a mounting device according to the invention ischaracterized in that it comprises alignment means adapted to befastened to the first mounting flange, the first mounting flange havinga first reference surface which is in a predetermined spacedrelationship with respect to an X-ray beam path of the radiation sourceand which corresponds with a second reference surface of the secondmounting flange. As a result, the first reference surface can easily beadjusted with respect to the path of the X-ray beam in the radiationsource. Subsequently, the radiation source and the beam manipulatingdevice can easily be fixed to each other in a precise and adjustedmanner by fastening the mounting flanges to each other.

It is an important advantage of the invention that the alignment meanscan be adjusted with respect to the beam and fixed to the radiationsource in the production process of the X-ray apparatus or the radiationsource, e.g. the X-ray tube. Once the alignment means are fixed, they donot have to be loosened in subsequent utilization and maintenanceprocedures. When, in a following step, the beam manipulating device hasto be mounted to the radiation source, this can be done in a simplemanner without the need of any adjustment, since the alignment of thebeam manipulating device with respect to the beam is secured by thefitting of the reference surface of the first mounting flange and thecorresponding reference surface of the second mounting flange. Thus, thealignment process is made part of the radiation source production, whichis independent of the production of the whole X-ray apparatus. Thissimplifies the adjustment process during apparatus production.

Another advantage of the invention becomes apparent when the beammanipulating device, or the radiation source, must be replaced whilewhen the X-ray apparatus is located at a customer's site. If, in thiscase, the beam manipulating device has to be replaced or exchanged foranother beam manipulating device, this can be performed without the needof any adjustment, since the alignment means do not have to be loosenedand therefore the reference surface of the alignment means remain inalignment with respect to the X-ray beam. By virtue thereof, thereplacement beam manipulating device having a corresponding referencesurface can simply be mounted to the radiation source of the X-rayapparatus. On the other hand, when the radiation source has to bereplaced, this can be done by replacing it with a new radiation sourcehaving alignment means with a reference surface adjusted in apredetermined spaced relationship with the X-ray beam of the source.This reference surface or these reference surfaces correspond with therespective surfaces of the second mounting flange of the beammanipulating device which remains in place. By virtue thereof, the newradiation source can be mounted to the beam manipulating device withoutthe need of any adjustment process.

Preferably the first and second reference surfaces are cylindrical. Inanother preferred embodiment the reference surfaces each comprise atleast two plane surfaces which are in angular relationship with eachother. The contact area between the reference surface of the firstmounting flange and the corresponding reference surface of the secondmounting flange must comprise at least two points which are separatefrom each other and which are capable of transmitting a contact force indirections which are not parallel to each other and not parallel to thedirection of the X-ray beam. By this, it is possible to define an exactalignment by these two points with respect to the X-ray beam.

In a preferred embodiment of the invention, the beam manipulating deviceis a collimator. In other embodiments, the beam manipulating device canbe a shutter mechanism or a diaphragm device or any other device whichis used to shape, focus, scatter, lead or amplify the X-ray beam.

The invention further relates to an X-ray apparatus with a radiationsource, a beam manipulating device and a mounting device for fasteningthe beam manipulating device and the radiation source to each other,wherein the mounting device is a mounting device according to theinvention.

Furthermore, the invention relates to a method for mounting a beammanipulating device to a radiation source of an X-ray apparatus,including the steps of adjusting a first reference surface of alignmentmeans with respect to an X-ray beam path of the radiation source,fastening the alignment means to a first mounting flange associated withthe radiation source, fitting a second reference surface, whichcorresponds with the first reference surface and which is comprised in asecond mounting flange associated with the beam manipulating device, tothe first reference surface, and fastening the first and the secondmounting flange to each other.

This method allows an easy adjustment process to align a beammanipulating device with respect to the X-ray beam of an X-ray apparatusand to fasten this beam manipulating device to a radiation source of theX-ray apparatus.

A preferred embodiment of the invention will be described with referenceto the Figures, wherein:

FIG. 1 is a front view of a mounting flange associated with a beammanipulating device,

FIG. 2 is a cut away side view along line A-A in FIG. 1 of the mountingdevice according to the invention,

FIG. 3 is a cut away side view along line B-B in FIG. 1 of the mountingdevice according to the invention, and

FIG. 4 is a cut away side view along line C-C of FIG. 1 of the mountingdevice according to the invention.

The embodiment shown in the Figures comprises an annular mounting flange20 associated with the beam manipulating device (not shown). Themounting flange 20 has a boring 21, the boring 21 and the mountingflange 20 being circularly arranged around a middle axis 22. Themounting flange 20 has a precisely machined outer diameter 24, whichfits a collimator which can be mounted to the forepart 23 of flange 20.The opposite forepart 25 of mounting flange 20 comprises an annularrecess containing an alignment ring 30. The outer periphery 31 ofalignment ring 30 fits exactly in the inner periphery (34) of theannular recess in forepart 25 of mounting flange 20. By virtue thereof,the alignment ring 30 has an exactly defined position relative to themounting flange 20.

Alignment ring 30 in the annular recess in forepart 25 and the remainingsurface of forepart 25 without the recess form a plane surface. A firstmounting flange 10 associated with the radiation source of the X-rayapparatus (not shown) is in slidable contact with this plane surface.Consequently, mounting flange 10 is movable in a direction perpendicularto middle axis 22, while staying in contact with the forepart of secondmounting flange 20 and/or the forepart of alignment ring 30. The firstmounting flange 10 comprises four threaded borings 11. First screws 40extending through respective borings 32 in the alignment ring 30 can bescrewed in the borings 11. When tightening the screws 40, the alignmentring 30 is fastened to the first mounting flange 10. It is important tonotice, that the boring 32 in alignment ring 30 is bigger than the outerdiameter of the screw 40. Thus, it is possible to move the alignmentring 30 and the first mounting flange 10 towards each other in adirection perpendicular to middle axis 22. Therefore, reference surface31 can be aligned with respect to the X-ray beam which is emittedthrough boring 21 in the direction of middle axis 22.

The second mounting flange 20 has four borings extending from therecessed relief 24 to the annular recess in the forepart 25. Theseborings 26 provide room for the screws 40, so that the head of thescrews 40 does not project into the recessed relief 24.

Furthermore, the second mounting flange 20 comprises four borings 28,each having a circular recess 29 facing the recessed relief 24. Each ofthe circular recesses 29 of borings 28 in the second mounting flange 20accommodates a circular insert 50. Each circular insert 50 has acentered conical boring accommodating the head of a countersunk headscrew 60. The countersunk head screws 60 extend through the borings 28in the second mounting flange 20 and through a co-axial boring 33 andare screwed into a co-axial threaded boring 12 in the first mountingflange 10.

It is important to notice that borings 28 and 33 are bigger than theouter diameter of the screw 60 and that the diameter of recess 29 islarger than the outer diameter of insert 50. Thus, it is possible tomove the second mounting flange 20 and the alignment ring 30 embeddedtherein into contact with the first mounting flange 10 when the screws40 are not tightened. Therefore, an alignment of the second mountingflange 20 with respect to the beam of the X-ray apparatus is possible.

Having described the mounting device according to the invention, themethod of mounting a beam manipulating device to a radiation source ofan X-ray apparatus will be explained as follows:

Mounting flange 10 is associated with the radiation source of the X-rayapparatus (not shown). The X-ray beam of the apparatus passes throughboring 13 of the first mounting flange 10 in the direction of the access22.

In a first step of the method, alignment ring 30 is put on the firstmounting flange 10 and the four screws 40 are screwed into the borings11 but are not tightened.

After this, the reference surface 31 of alignment ring 30 is alignedwith respect to the X-ray beam of the apparatus, using for example anauxiliary device for detection of the exact position and direction ofthe beam. When the reference surface 31 of alignment ring 30 has beenadjusted, the ring will not be moved into contact with the firstmounting flange 10 anymore. The four screws 40 are then tightened andalignment ring 30 is thereby fastened to the first mounting flange 10.

After this, the second mounting flange 20 of the beam manipulatingdevice (not shown) may easily be adapted to the apparatus and hence isautomatically aligned with respect to the X-ray beam. This is achievedby the reference surface 31 which is accommodated in the annular recessin the forepart 25 of second mounting flange 20. A movement of thesecond mounting flange 20 perpendicularly to the center line 22 isrestricted by the fit of the alignment ring 30 in said annular recess.

The second mounting flange 20 may afterwards be fastened to the firstmounting flange 10 by inserting the four screws 60 with the four inserts50 into the borings 28, 33 and into the circular recess 29 and screwingthese screws 60 into the threaded borings 12.

The advantage of the above-described mounting device and mounting methodresides in that only a lightweight alignment ring has to be adjustedwith respect to the path of the X-ray beam. This alignment ring can befixed in the adjusted position and does not have to be loosened whenreplacement of either the source or the manipulating device becomesnecessary at a later stage. The alignment ring has a reference surface,allowing to fix other devices with respect to the path of the beam in aprecise and easy manner. By virtue thereof, there is no need to repeatthe adjustment procedure after such a replacement.

It is important to notice that the mounting flanges could either beseparate parts of the system, in which case they are fastened to theradiation source or to the beam manipulating device, or be part of thehousings of the radiation source or the beam manipulating device.

1. A mounting device for mounting a radiation source of an X-rayapparatus, said mounting device comprising: a first mounting flangeassociated with the radiation source, and having a first aperturetherethrough, a second mounting flange having a second aperturetherethrough and a recess therein, one or more first fastening devicesfor fixing the first mounting flange and the second mounting flange toeach other, an alignment ring adapted to be fastened to the firstmounting flange and positioned in the recess of the second mountingflange, and one or more second fastening devices for fixing thealignment ring and the first mounting flange to each other, wherein eachof the one or more first fastening devices is separated from thealignment ring and the second mounting flange along a radial directionby one or more first spaces, and wherein a beam of the radiation sourcepasses through the first and second apertures.
 2. A mounting device asclaimed in claim 1, wherein each of the one or more second fasteningdevices is separated from the alignment ring and the second mountingflange along a radial direction by one or more second spaces.
 3. Amounting device as claimed in claim 2, wherein the one or more secondspaces are bores defined through the alignment ring and second mountingflange, and wherein the bores have diameters that are larger thandiameters of the one or more second fastening devices.
 4. A mountingdevice as claimed in claim 1, wherein the one or more first spaces arebores defined through the alignment ring and the second mounting flange,and wherein the bores have diameters that are larger than diameters ofthe one or more first fastening devices.
 5. A mounting device as claimedin claim 1, wherein the recess has a size and shape to prevent radialmovement of the alignment ring with respect to the second mountingflange.
 6. The mounting device of claim 1, wherein the first mountingflange and the alignment ring abut against each other only along asingle planar surface.
 7. The mounting device of claim 6, wherein thefirst mounting flange and the second mounting flange abut against eachother only along a single planar surface.
 8. An X-ray apparatuscomprising: a radiation source, a beam manipulating devices, and amounting device for fastening the beam manipulating device and theradiation source to each other, wherein the mounting device has a firstmounting flange associated with one of the radiation source and the beammanipulating device, a second mounting flange associated with the otherof the radiation source and the beam manipulating device, and analignment ring adapted to be fastened to the first mounting flange,wherein one or more fastening devices fix the first mounting flange, thesecond mounting flange and the alignment ring to each other, wherein theone or more fastening devices pass through bores in the second mountingring and the alignment ring, and wherein the bores have diameters thatare larger than diameters of the one or more first fastening devicesthereby allowing the first mounting flange to slide with respect to thesecond mounting flange and the alignment ring.
 9. The X-ray apparatus ofclaim 8, wherein the one or more fastening devices are first and secondsets of screws, wherein the first set of screws secure the firstmounting flange with the alignment ring, and wherein the second set ofscrews secure the second mounting flange with the alignment ring. 10.The X-ray apparatus of claim 9, wherein the first mounting flange andthe alignment ring abut against each other only along a single planarsurface.
 11. The X-ray apparatus of claim 10, wherein the first mountingflange and the second mounting flange abut against each other only alonga single planar surface.
 12. The X-ray apparatus of claim 8, wherein thesecond mounting flange has an annular groove therein, and wherein thealignment ring is positioned in the annular groove.
 13. The X-rayapparatus of claim 12, wherein the annular groove has a size and shapeto prevent radial movement of the alignment ring with respect to thesecond mounting flange.
 14. A method for mounting a beam manipulatingdevice to a radiation source of an X-ray apparatus, including the stepsof: slidably connecting a first mounting flange to an alignment ring,the first mounting ring being associated with the radiation source;aligning a beam of the radiation source with the alignment ring byradially sliding the alignment ring with respect to the first mountingflange; securing the first mounting flange with respect to the alignmentring to prevent any sliding; securing a second mounting flange to thealignment ring, the second mounting flange being associated with thebeam manipulating device.
 15. The method of claim 14, further comprisingpositioning the alignment ring in a groove formed in the second mountingflange.
 16. The method of claim 14, further comprising positioning thealignment ring in a groove formed in the second mounting flange toprevent radial movement of the alignment ring with respect to the secondmounting flange.
 17. The method of claim 14, further comprisingproviding one or more first fastening devices for securing the firstmounting flange and the alignment ring to each other, wherein each ofthe one or more first fastening devices is separated from the alignmentring and the second mounting flange along a radial direction by one ormore first spaces.
 18. The method of claim 14, further comprisingproviding one or more second fastening devices for securing the firstand second mounting flanges to each other, wherein each of the one ormore second fastening devices is separated from the alignment ring andthe second mounting flange along a radial direction by one or moresecond spaces.
 19. The method of claim 14, further comprising abuttingthe first mounting flange and the alignment ring only along a singleplanar surface.
 20. The method of claim 19, further comprising abuttingthe first mounting flange and the second mounting flange only along asingle planar surface.